I have a steel cylinder with flash rust from the last hydro. Has two gallons of evapo-rust in it.

[rob.mwpropane]

Excuse my ignorance, how much flash rust is considered bad? I understand if it's for an O2 bottle, or PP filling it needs to be extra clean.

I ask as I bought a set of tanks last year. The LDS that I took them to popped the valve off and let me look inside. I was surprised to see rust, but it wasn't a lot. He said it was fine and said they all have some rust. Put the valve back on and filled.

Thanks, sorry to jack you thread.

 

[rjack321]

Excuse my ignorance, how much flash rust is considered bad? I understand if it's for an O2 bottle, or PP filling it needs to be extra clean.

I ask as I bought a set of tanks last year. The LDS that I took them to popped the valve off and let me look inside. I was surprised to see rust, but it wasn't a lot. He said it was fine and said they all have some rust. Put the valve back on and filled.

Thanks, sorry to jack you thread.

this is taught in a vip class

 

[rob.mwpropane]

this is taught in a vip class

If it's the LDS that allowed the surface rust to be in the tanks in the 1st place, and I take a VIP class there, obviously the amount of rust left was considered ok? I doubt I would get my question answered.

It's not a very technical question. I just wanted to see what the collective opinion on SB was. Any single instructor can be wrong, but collectively in a group setting it's harder to be lead in the wrong direction.

Truth be told, I plan to set my singles up as doubles soon and fill with a whip. I'm not paying for another VIP when it was just done 5 months ago, so I'd like to know should I get the rust out, or not a big deal?

I always appreciate everyone's time and knowledge though, great thread!

 

[rddvet]

I don't know why you'd want to do this pre-hydro. Do it post because I guarantee you'll have more. We're spoiled here in florida. The hydro guy everybody in cave country uses puts rust inhibitor in steel tanks, uses warm super filtered water to clean them out, and dries them immediately with hot hair. Never get any flash rust from Dave.

 

[Rusty Shackleford]

My guy has rust inhibitor. I mixed him up a gallon.

 

[Nino5206]

Hi Rusty,

What mix ratio did you use for the Evapo-rust also did you just flush it with cold water then immediately dry with scuba air afterwards?

I'm keep getting a thin layer of flash rust after tumbling my tanks with media and a bit of simply green.

thanks

 

[aviator8]

I used water rinsed then blue gold to clean and several rinses of water after evaporust. I did not use the rust inhibitor, but made sure to thoughtfully dry with hot air then transfill. I guess Ill know for sure at next vip but there was no sign of any rust when I closed them up.

 

[Ghost95]

The non scuba hydro place near me doesn't dry scuba tanks. They always have flash rust less than 24 hrs afterward and have to be tumbled to pass VIP. Cheaper to just take them to the dive shop.

I don't know about your particular location but from experience I do know that many, if not most dive shops, subcontract their hydro work. The equipment required is expensive and many shops cant afford the price to have a hydro setup and crew on staff.

I know locally our shops take them to a fire extinguisher shop to get the hydros done and then they pick them up and do the visuals and fill. The shops wait until they have batches of tanks to take in for hydro so sometimes you have a long wait to get the work done.

I have found it cheaper and more convenient to just deliver the tank to the same hydro place and then pick it up in a few days and take it to the shop. There is no mark up on the hydro when I do this. The dive shop needs to be paid for their delivery and pickup of the tanks but I just do it when I'm out and about anywha.

I also get to chat with the hydro guys. Last time I was in the shop I asked how many old steel tanks he's seen fail and he said very, very, very few. Aluminum was another story.

 

[greeniguana]

I don't know about your particular location but from experience I do know that many, if not most dive shops, subcontract their hydro work. The equipment required is expensive and many shops cant afford the price to have a hydro setup and crew on staff.

I know locally our shops take them to a fire extinguisher shop to get the hydros done and then they pick them up and do the visuals and fill. The shops wait until they have batches of tanks to take in for hydro so sometimes you have a long wait to get the work done.

I have found it cheaper and more convenient to just deliver the tank to the same hydro place and then pick it up in a few days and take it to the shop. There is no mark up on the hydro when I do this. The dive shop needs to be paid for their delivery and pickup of the tanks but I just do it when I'm out and about anywha.

I also get to chat with the hydro guys. Last time I was in the shop I asked how many old steel tanks he's seen fail and he said very, very, very few. Aluminum was another story.

My LDS is also a DOT certified hydro tester. I don't have to worry about taking my worthington and pst tanks to them, so I don't mind paying a tad more.

I talk to my fire extinguisher hydro guys too. They still don't dry scuba tanks correctly ;^) I will continue to take my beer CO2 tanks there though. I have a steel CO2 tank from the 80s, never had an issue. The shop told me they frequently test and pass steel tanks from the 40s and 50s.